Castle 6×05 “Time Will Tell” – A grisly murder investigation leads Castle and Beckett to a suspect (Joshua Gomez, “Chuck,” guest stars as Simon Doyle) who claims he’s traveled back in time to stop terrible events from unfolding, events that will change the course of human history. Is he simply a deluded killer, or is it possible that he’s telling the truth, on Castle, Monday, October 21st on ABC.